I am getting some estimates to fix some ducting issues that I cannot fix myself. What is the going rate for a contractor when installing new ductwork. The ducting is a 20ft run and is completely accessible from the basement.

for both heat and ac? The ductwork i had run in my walls while they were open was pretty cheap ~1500. I had ductwork run from the attic to both floors. Since your just doing it in the basement, i bet it should be half of what i paid since I'm guessing you are just replacing whats there not running new lines.

The air handler and condenser were a pretty penny, but make sure to pull permits